[asterisk-users] meetme conference using g729?

[Steve Totaro]

If bandwidth were not an issue, I would think everyone would opt for 
ulaw or alaw.  Why compress and use CPU cycles and G729 licenses if 
there were no bandwidth issues?

Thanks,
Steve totaro

Wai Wu wrote:
> But his preference of G729 is to save bandwidth.
>
> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com
> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Tim Panton
> Sent: Wednesday, October 03, 2007 8:16 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [asterisk-users] meetme conference using g729?
>
> Not exactly.
> Here are the facts:
> 	meetme mixes in SLIN.
> 	Any data arriving in anything other than slin will get
> transcoded twice,
> 		once on the way in and again on the way out.
>
> Now some opinions:
> 	The more efficient the compression of the codec, the less well
> it copes with
> 	decoding and re-encoding. Ulaw and Alaw are simple and not that
> efficient,
> 	but you don't lose any more by re-encoding than you did by
> decoding in the first place.
> 	Tighter codecs like 729 and GSM you will definitely hear the
> difference.
>
>
> Theory:
> 	If you have a conference where there is only _ever_ one speaker
> 	at a time, you could (in theory) optimize meetme to do without
> mixing, and if all
> 	the participants were using the same codec, you could get away
> with not re-encoding
> 	by sending out the appropriate incomming packet to all (other)
> members.
> 	I'm guessing that isn't the case for you.
>
> Advice:
> 	use Ulaw - it's a decent tradeoff for this sort of thing.
>
> Tim.
>